scholarly journals The Role of Brønsted and Lewis Acid Sites of Vanadyl Pyrophosphate Measured by Dimethylpyridine-temperature Programmed Desorption in the Selective Oxidation of Butane

2003 ◽  
Vol 46 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Yuichi KAMIYA ◽  
Hiroyuki NISHIYAMA ◽  
Miki YASHIRO ◽  
Atsushi SATSUMA ◽  
Tadashi HATTORI
Keyword(s):  
Selective Oxidation ◽  
Lewis Acid ◽  
Temperature Programmed Desorption ◽  
Acid Sites ◽  
Vanadyl Pyrophosphate ◽  
Lewis Acid Sites ◽  
Temperature Programmed ◽  
Brønsted And Lewis Acid

scholarly journals Liquid Phase Benzylation of Toluene over Modified Titania Catalysts

2012 ◽  
Vol 11 (2) ◽  
pp. 31-44
Author(s):  
Sunaja Devi K R ◽  
Sugunan S
Keyword(s):  
Liquid Phase ◽  
Lewis Acid ◽  
Benzyl Chloride ◽  
Sol Gel ◽  
Active Phase ◽  
Temperature Programmed Desorption ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Sulfated Titania ◽  
Temperature Programmed

Titania, sulfated titania and a series of iron loaded sulfated titania catalyst with different iron loadings (39 %) are prepared by sol-gel method and calcined at 500°C. Anatase is found to be the active phase with crystallite size in the nano range. All the prepared catalysts are found to be stable up to 700°C. Acidity is measured using spectrophotometric monitoring of adsorption of perylene, thermogravimetric desorption of 2,6-dimethylpyridine and temperature programmed desorption of ammonia. The activities of the catalysts were tested for liquid phase Friedel-Crafts benzylation of toluene with benzyl chloride. It has been concluded that Lewis acid sites are responsible for the reaction.

scholarly journals Solid Acids for the Reaction of Bioderived Alcohols into Ethers for Fuel Applications

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 172 ◽  
Author(s):  
Federica Zaccheria ◽  
Nicola Scotti ◽  
Nicoletta Ravasio
Keyword(s):  
Physical Properties ◽  
Lignocellulosic Biomass ◽  
Lewis Acid ◽  
Product Distribution ◽  
Acid Sites ◽  
Solid Acids ◽  
Lewis Acid Sites ◽  
Hydroxymethyl Furfural ◽  
Brønsted And Lewis Acid

The use of solids acids in the synthesis of ethers suitable to be used as fuels or fuel additives were reviewed in a critical way. In particular, the role of Brønsted and Lewis acid sites was highlighted to focus on the pivotal role of the acidity nature on the product distribution. Particular emphasis is given to the recently proposed ethers prepared starting from furfural and 5-hydroxymethyl furfural. Thus, they are very promising products that can be derived from lignocellulosic biomass and bioalcohols and possess very interesting chemical and physical properties for their use in the diesel sector.

Role of Brønsted and Lewis acid sites on Ni/TiO2 catalyst for vapour phase hydrogenation of levulinic acid: Kinetic and mechanistic study

2015 ◽  
Vol 505 ◽  
pp. 217-223 ◽  
Author(s):  
Velisoju Vijay Kumar ◽  
Gutta Naresh ◽  
Medak Sudhakar ◽  
James Tardio ◽  
Suresh K. Bhargava ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Levulinic Acid ◽  
Vapour Phase ◽  
Acid Sites ◽  
Mechanistic Study ◽  
Lewis Acid Sites ◽  
Tio2 Catalyst ◽  
Brønsted And Lewis Acid

scholarly journals Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

Catalysts ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 211 ◽  
Author(s):  
Serguei Alejandro-Martín ◽  
Héctor Valdés ◽  
Marie-Hélène Manero ◽  
Claudio Zaror
Keyword(s):  
Lewis Acid ◽  
Natural Zeolite ◽  
Acid Sites ◽  
Catalytic Ozonation ◽  
Lewis Acid Sites ◽  
Brønsted And Lewis Acid

The Role of Brønsted and Lewis Acid Sites in Acetalization of Glycerol over Modified Mesoporous Cellular Foams

2016 ◽  
Vol 120 (30) ◽  
pp. 16699-16711 ◽  
Author(s):  
Katarzyna Stawicka ◽  
Alba E. Díaz-Álvarez ◽  
Vanesa Calvino-Casilda ◽  
Maciej Trejda ◽  
Miguel A. Bañares ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Cellular Foams ◽  
Brønsted And Lewis Acid

Comprehensive Understanding of the Role of Brønsted and Lewis Acid Sites in Glucose Conversion into 5-Hydromethylfurfural

ChemCatChem ◽  
2017 ◽  
Vol 9 (14) ◽  
pp. 2739-2746 ◽  
Author(s):  
Xiangcheng Li ◽  
Kaihao Peng ◽  
Xiaohui Liu ◽  
Qineng Xia ◽  
Yanqin Wang
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Comprehensive Understanding ◽  
Lewis Acid Sites ◽  
Brønsted And Lewis Acid

scholarly journals Effect of Zn/ZSM-5 and FePO4Catalysts on Cellulose Pyrolysis

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Haian Xia ◽  
Xiaopei Yan ◽  
Siquan Xu ◽  
Li Yang ◽  
Yuejie Ge ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Value Added ◽  
Product Distribution ◽  
Acid Sites ◽  
Gas Chromatography Mass Spectrometry ◽  
Lewis Acid Sites ◽  
Liquid Products ◽  
Temperature Programmed ◽  
Xrd Techniques ◽  
Brønsted And Lewis Acid

A series of Zn/ZSM-5 catalysts with different Zn contents and FePO4were used to pyrolyze cellulose to produce value added chemicals. The nature of these catalysts was characterized by ammonia-temperature programmed desorption (NH3-TPD), IR spectroscopy of pyridine adsorption, and X-ray diffraction (XRD) techniques. Noncatalytic and catalytic pyrolytic behaviors of cellulose were studied by thermogravimetric (TG) technique. The pyrolytic liquid products, that is, the biooils, were analyzed by gas chromatography-mass spectrometry (GC-MS). The major components of the biooils are anhydrosugars such as levoglucosan (LGA), 1,6-anhydro-β-D-glucofuranose (AGF), levoglucosenone (LGO, 1,6-anhydro-3,4-dideoxy-β-D-pyranosen-2-one), and 1,4:3,6-dianhydro-α-D-glucopyranose (DGP), as well as furan derivatives, alcohols, and so forth. Zn/ZSM-5 samples with Brønsted and Lewis acid sites and the FePO4catalyst with Lewis acid sites were found to have a significant effect on the pyrolytic behaviors of cellulose and product distribution. These results show that Brønsted and Lewis acid sites modified remarkably components of the biooil, which could promote the production of furan compounds and LGO. On the basis of the findings, a model was proposed to describe the pyrolysis pathways of cellulose catalyzed by the solid acid catalysts.

Sign in / Sign up

Export Citation Format

Share Document